软件定义网络中分布式控制器的在线更换机制

Online Swapping of Distributed Controllers in Software Defined Networks

软件定义网络技术通过将控制和转发功能分离,并使用控制器进行集中式的网络控制,实现了网络的灵活控制和管理,近年发展迅速且得到日益广泛的应用.在以大型数据中心为代表的大规模网络中,通常需要部署多台分布式SDN控制器以确保网络性能及可靠性,这些控制器长时间持续运行,其硬软件升级和更换需要在线完成,且需保证服务不中断.本文针对这一问题,提出了一种SDN控制器的在线更换机制,实现分布式控制器的在线更换和连续服务,同时针对控制器更换后性能异构带来的负载不均衡问题,给出了异构控制器间的负载均衡算法.论文最后通过实验测试验证了所提出方法的有效性.

Software Defined Networking(SDN)decouples control plane from data plane in networks,and controls networks using centralized controllers,finally achieves flexible control and management over networks.To ensure performance and reliability in largescale SDN networks such as datacenters,it is necessary to deploy distributed controllers to provide scalable and continuous services.In such kind of environment,hardware/software upgrading of controllers requires online swapping of specified nodes,while both the service interruption of controllers and processing errors are not allowed.In addition,load-balancing needs to be re-considered since the hardware of controllers may become heterogeneous after swapping.To address this problem,this paper proposes an online swapping mechanism for distributed SDN controllers;in addition,a load-balancing algorithm for heterogeneous controllers is also presented to ensure that network switches utilize resources of the new controller efficiently.Experimental results demonstrate effectiveness of the mechanism.